Reading UBC Tables

Robert Hennings

Where can I get information on how to correctly read the UBC tables for joists and rafters to select the proper sizes for the spans?

mdshunk

Are you sure you're actually still under the UBC? I'd hate to see you put effort into figuring out the wrong code book.

Robert Hennings

Thank you for giving a response but you did not give any leads as to how to properly read these tables. Does anyone care to give help?

mdshunk

I know. I answered your question with a question, which you cared not to answer. When a person referrs to the UBC in these times, that raises a red flag. Most people are on the IRC/IBC now. It would be reasonably important to a person who might choose to spend their time answering your question whether that code text really applies.

K2

I think/heard that most of California is still on the ubc because it is a stricter code and because Robert's trade name is Don Bosco Tech and because i think the only Don Bosco left is in California, Robert is still probably on the UBC.

I had a book and maybe still have it somewhere called " The ubc in plain English"

I worked under the UBC for 25 years and am reasonably good at math. I used more simplified equations and almost always passed at our building dept.

That probably doesn't aswer your question either Robert. I think there are some engineering forum around that you might post on.

Robert Hennings

Thank you for your response. Yes, I am in California and yes the UBC, although dated, is still the base code with other local codes tagged on to it. I appreciate your reply but as you say it does not answer my question as far as what is the name of a resource. I would still appreciate any resource name that might give a full explaination of the UBC joist and rafter tables

K2

Ok, I just dug out my 1985 ubc and it seems I threw the rest away but the 85 was buried.

Looks like each species of lumber is given a fb number = exteme stress in fiber bending and an E= modules of elasticity. Table 2504. Take that over to the tables around 25-U. and plug in your Fb and E and get your spans. For multiple members there is an equation or two that you have to use. Looks pretty simple for single members.

Where's Teetor?? He's the engineer. he can probably explain these things. I'm still looking for my UBC in plain English.

K2

Contractor's Guide to the Building Code By Jack M. Hageman.

Explains in plain English exactly what the '97 Uniform Building, Plumbing, & Mechanical Codes require. This will help you pass those inspections the first time. Tips cover the items most cited and how to avoid them. For both residential and commercial.

This is the book I was referring to but how much discussion is on the rafter/joist tables I don't remember.

Robert Hennings

Thank you K2eoj for your help with the UBC tables. I will look for this book.
Once again, thank you.